The image alone is worth reposting!
To recap their article: Do it because it’s fun and feels really good. It’s also still taboo, which adds to the thrill!
To prep, make sure your partner bathes thoroughly first. Then, do your normal foreplay. But knowing what’s going to happen will add a certain thrill and excitement level.
Then start to caress their ass. Cup their cheeks in your hands and squeeze. Trace a fingertip along the area where their butt cheeks meet their thighs. You can also kiss and lick along their cheeks. Tease your partner along their butt crack, starting to venture towards the anus but not quite hitting it.
…work your tongue around the anus. Going in circles is the easiest technique. You can adjust the diameter of your circles, moving farther apart and then closer together. Or try doing figure-eights, crossing over the anus itself.
If you and your partner are enjoying your rimming adventure, try squeezing their cheeks and pulling them wider apart. This will expose even more area for you to work with, and feels great for your partner.